Was that any particular Baccus army deal or was it cobbled together from seperate packs?
Everything in the army was pulled from a Warmaster Army pack sold by Baccus, except... the strips of Numidian Horse, and extra unit of artillery. All in all, if you plan how you are laying out your bases, you can do a 6mm army for Impetus very cheaply. I would recommend looking at one of their army packs, and counting out how many strips of each unit type are included. For my force, I went with 6 strips of infantry per base, 4 strips of cavalry for medium cavalry, 2 strips of cavalry for light cavalry, and around 5 or six models for each unit of skirmishers.
I plan on doing Skythians next. Tons and tons of light horse!